1. Field of the Invention
This invention relates to a self-cleaning plate shaped device which, for example, can be utilized to remove foreign substances from a plate member such as an automotive rear mirror.
2. Description of the Related Art
Japanese laid-open patent publication No. 59-8548 published on Jan. 17, 1984 discloses a conventional cleaning device for an automotive rear view mirror (see FIG. 14). The cleaning device preferably includes a plate member 1 which is a rear-view mirror for an automobile. A piezoelectric vibrator 2 is affixed to the plate member 1. An oscillator 3 is electrically connected to the vibrator 2 in order to supply A.C. power. When the plate member 1 is oscillated by the vibrator 2, water droplets on the plate member 1 are removed. The water droplets drip off or are atomized into a spray.
Japanese utility model laid-open patent publication No. 59-40145 published on Mar. 14, 1984 discloses another conventional cleaning device. (see FIG. 15). In this device, a heater 4 is affixed to a plate member 1 in order to heat the plate member 1. When the plate member 1 is heated by the heater 4, water drops on the plate member 1 are evaporated due to the electric power supplied across the terminals 5 and 6.
The vibrator 2 of Japanese Patent Publication No. 59-8548 can remove the water drops relatively quickly, but it cannot generate enough heat for melting and removing frost and ice on the plate member 1. On the other hand, the heater 4 of Japanese Patent Publication No. 59-40145 can remove water drops, frost and ice, but the heater 4 requires a relatively long time.